Response Matrix for Landfills

In all cases standards prescribed in the EPA Landfill Site Design Manual (EPA,1999) or conditions of a waste licence will apply.

R1 Acceptable subject to guidance in the EPA Landfill Design Manual or conditions of a waste licence.

R2¹ Acceptable subject to guidance outlined in the EPA Landfill Design Manual or conditions of a waste licence.

• Special attention should be given to checking for the presence of high permeability zones. If such zones are present then the landfill should only be allowed if it can be proven that the risk of leachate movement to these zones is insignificant. Special attention must be given to existing wells down-gradient of the site and to the projected future development of the aquifer.

R2² Acceptable subject to guidance outlined in the EPA Landfill Design Manual or conditions of a waste licence.

• Special attention should be given to checking for the presence of high permeability zones. If such zones are present then the landfill should only be allowed if it can be proven that the risk of leachate movement to these zones is insignificant. Special attention must be given to existing wells down-gradient of the site and to the projected future development of the aquifer.

• Groundwater control measures such as cut-off walls or interceptor drains may be necessary to control high water table or the head of leachate may be required to be maintained at a level lower than the water table depending on site conditions.

R3¹ Not generally acceptable, unless it can be shown that:

• the groundwater in the aquifer is confined; or

• there will be no significant impact on the groundwater; and

• it is not practicable to find a site in a lower risk area. R32 Not generally acceptable, unless it can be shown that:

• there is a minimum consistent thickness of 3 metres of low permeability subsoil present;

• there will be no significant impact on the groundwater; and

• it is not practicable to find a site in a lower risk area.

R4 Not acceptable.

• This guidance is for the siting of landfills for non-hazardous wastes.

• New landfills should not generally be developed on regionally important aquifers.

• The siting, design, operation and monitoring of landfills must comply with the guidelines outlined in the EPA’s Landfill manuals except where facilities hold a waste licence issued by the EPA.

• It is recommended that all landfills be located in, or as near as possible to, the zone in the bottom right hand corner of the matrix.

• Special attention should be given to checking for the presence of more permeable zones, such as faults, particularly in fractured bedrock.